Autobullectomy: Disease Itself Relieved The Dyspnoea of Patient. Can It Happen?

Pulmonary bullae occur as insulated abnormalities in approximate normal lung tissue or in the presence of emphysema. The steady expansion of lung bulla is common; however, its mechanism is still unclear, but can impulse life threatening conditions that requires emergent surgical intervention. Spontaneous complete or partial resolution also known as “autobullectomy” of giant pulmonary bullae is very scarce. The pathophysiology of natural purging of giant bulla is not known with inevitability. Here, we are discussing a case of an older female presented with exertional dyspnoea and later diagnosed as large bullous emphysema with secondary infection on the left side. She was managed with antibiotics and inhaled bronchodilators, showed near complete spontaneous resolution of a giant pulmonary bulla with dramatic improvement in severity of dyspnoea, partial pressure of oxygen and arterial blood gas.


Introduction
Bullous lung disease is a common presentation in patients with chronic obstructive pulmonary diseases (COPD) and the upshot of the inhalation of combusted tobacco products. Its occurrence in female is very unusual.
The development of small multiple bullae are common, but the existence of giant bullae is usually erratic.
The giant pulmonary bulla occupies one third of the involved hemi-thorax and characterized by the existence of centrilobular emphysema in the non-bullous lung.
Giant bulla slowly increases in size over time and causes compressive atelectasis of lung parenchyma resulting respiratory compromises [1]. Sometime air reabsorbs spontaneously leading to shrinkage and regression of bullae known as autobullectomy [2]. Eleven cases of complete resolution and six cases with partial regression of giant bullae are recorded in the English literature [3].
Here, we are discussing a case of spontaneous resolution of giant bullae following an infectious episode in an older age female managed symptomatically.

Case history
A 50 years old female with a previous history of twenty pack-years tobacco smoking came to the pulmonary outpatient department with complaints of progressive increase in breathlessness on exertion since one year and modified medical research council (MMRC) grade 2 to grade 3 in last one month along with cough, mucoid expectoration and fever of twenty days duration. She was neither diabetic nor hypertensive. On admission, she was febrile, her pulse rate was 110 beats/minutes, blood pressure 130/90 mm of Hg, respiratory rate 30breaths / minutes and oxygen saturation was 85% on room air. The clinical appearance vary from asymptomatic bullous lung disease to mild cough, dyspnoea and fever to severe lower respiratory infection and influenced by size

International journal of Pulmonary & Respiratory Sciences
and infective pathology in bulla, adjacent lung parenchyma and lung compliance that explain the need of mechanical ventilator support [7]. The infected emphysematous bulla (air fluid level) is more symptomatic and warrants an aggressive management strategy. Bhardwaj et al. [8] explain the formation of air fluid level by two means. The gases within non-communicating space are now slowly absorbed, resulting loss of volume and eventually collapse of the giant bullae [9]. As this hypothesis explains spontaneous resolution of bulla in our case. Sometimes, tumour, mucous plug or a blood clot can also barricade an already bargained bronchial communication ensuing in a closed space [10]. Smoking cessation also improves the lung function as it decreases airway irritations. The uses of inhaled bronchodilators and anti-inflammatory medication also play a vital role in the resolution or regression of the giant bullae as they decrease in airway inflammation and thereby relieved a check-valve hence improve in severity in dyspnoea as in our case [11].

Conclusion
Spontaneous resolution of giant bullae also known as autobullectomy is an ignorant event and follows an infectious event. The giant bulla closely mimics to lung cancer and lung abscess so all patients should undergo direct visualization of airway by fibre-optic bronchoscopy.
Smoking cessation and intensification of inhaled bronchodilators should be instituted in all patients with giant bullae that may mitigate its progression to ventilator failure. The early suspicion and diagnosis by the treating physician can avert the need for a surgical bullectomy in these patients and decline the morbidity and mortality.
Our case is of interest not only because of the rarity with which spontaneous regression has been reported in the literature, but also because it was associated with such dramatic improvements in severity of dyspnoea, partial pressure of oxygen and arterial blood gas.